This invention relates to ultraviolet curable coating compositions. More particularly, this invention relates to ultraviolet curable coating compositions which are polymerizable more completely.
Because of the low incident energy utilized and the limited reaction time due to rapid crosslinking in ultraviolet coatings, most of these coatings are not completely cured after ultraviolet exposure. Often as high as twenty to forty percent of the unsaturated groups initially present in the coating remain present after exposure to ultraviolet radiation. Thus, ultraviolet curable coatings after initial curing are not as completely cured as might be desirable. Furthermore, the remaining unsaturation groups are subject to attack from a variety of sources, including sulfur dioxide, oxygen, oxidizing agents, reducing agents, solvents, sunlight, mineral acids, and the like.
The use of certain types of unsaturated ether compounds in ultraviolet curable coating compositions is known. See U.S. Pat. No. 3,380,831. However, these compositions become tied into the ultraviolet composition itself through the unsaturation present, thereby limiting their ability to defuse and react.
Thus, it is an object of this invention to prepare ultraviolet curable coating compositions.
It is another object of this invention to prepare ultraviolet curable coating compositions which, after exposure to ultraviolet light, are more completely cured.
It is another object of this invention to prepare ultraviolet curable coating compositions which exhibit improved chemical resistance, adhesion, and the like.
These and other objectives are obtained by preparing the compositions of the instant invention.